Solid-State Batteries – Toward High-Energy and High-Power Cells

Jürgen Janek

Professor of Physical Chemistry, Justus-Liebig-Universität Gießen & Karlsruhe Institute of Technology

Abstract

Lithium-ion batteries (LIB) have become within the last 30 years the leading electrochemical energy storage devices, with a wide range of applications from mobile electronics and electric vehicles to stationary storage. Today´s LIB cells rely almost exclusively on liquid electrolytes, a graphite negative electrode and a metal oxide positive electrode. This type of cell is approaching its natural limits in terms of energy stored per mass or volume, while its rate capability appears still to improve.

Solid-state batteries (SSB) rely on a solid electrolyte and are investigated world-wide as a realistic option toward cells with a mass or volume specific energy beyond the limits set by LIB. This effort is fueled by the development of solid electrolytes with an ionic conductivity higher than that of liquid electrolytes and the hope that high-capacity negative electrodes like lithium metal or silicon can be utilized.

In this lecture, an overview on the various solid-state cell concepts and their stage of development will be given first, highlighting the different types of solid electrolytes. The most promising cell concepts will be discussed in more detail, and key challenges will be considered.

In major part of the lecture, recent own results on the lithium metal anode and on cathode composites and coatings will be presented. Cells based on sulfide- and garnet-type electrolytes will mostly be considered. The status of sodium solid-state cells as an option for batteries with a less critical materials supply will be added as outlook.

Bio

Jürgen Janek is a full professor for Physical Chemistry at Justus Liebig University in Giessen (JLU), Germany, is director of the JLU Center for Materials Research and Scientific Director of the BELLA lab at KIT, Karlsruhe. He was visiting professor at Seoul National University (South Korea), Tohoku University (Sendai, Japan) and D’Aix-Marseille University (France), holds an honorary doctorate by TU Delft (Netherlands), is member of the Leopoldina – German National Academy of Sciences and was recently awarded with the first Greve Prize by Leopoldina. He holds numerous patents, has published more than 450 peer-reviewed papers and got numerous awards. His research interests focus on the physical chemistry of inorganic solids, solid state ionics and reactivity, specifically on the properties of mixed ionic-electronic conductors, defect chemistry of ionic materials, kinetics of solid-state reactions and solid-solid interfaces. In recent years his research is focused strongly on the chemistry of battery materials, solid electrolytes and solid-state batteries and operando studies of batteries. He is scientific coordinator of the German Cluster of Competence for Solid State Batteries FestBatt funded by BMBF (Federal Ministry for Education and Research) and member of the DFG Cluster of Excellence POLiS at Ulm/Karlsruhe.